The most common type of salivary gland swelling happens when salivary mucoceles form near an affected gland. These mucoceles are sometimes referred to as ranulas or salivary cysts. When a gland is damaged, usually from trauma, it can begin to leak saliva into surrounding tissue. The saliva accumulation irritates the tissue, causing an inflammatory response to wall off the collection of fluid. A salivary fistula is another cause of salivary gland swelling. Once again, trauma to the gland causes an excess of saliva to be produced, which can prevent wounds in the mouth from healing. A fistula (opening) can then develop at the wound site. Both of these conditions can range in severity, from mild to life-threatening.

The salivary glands produce saliva which assists the digestion process by lubricating chewed food. Cats have five different salivary glands including the mandibular, molar, parotid, sublingual and zygomatic. These glands are located on either side of the mouth, under the tongue, and near the throat. Swelling of these glands usually indicates injury has happened, and can create other oral health problems.

Symptoms and their severity will differ depending the location and size of the cyst or fistula. Many symptoms will deter the cat from eating, which can lead to dangerous weight loss. Symptoms to watch for include:

While trauma may cause salivary gland swelling, often the condition appears spontaneously. There are many possible contributing factors to the swelling, though none are definitive. Potential causes include:

The veterinarian will need all records of the cat’s medical history. A physical examination will be performed with focus in and around the mouth. The vet will palpate the face, throat and neck to check for swelling and mucoceles. There are other oral issues that share some of the symptoms of salivary gland swelling that will have to be ruled out, including cancer, a foreign object, growths, or dental abscesses. 

A fine needle aspiration biopsy is the best way to reveal if a mucocele is present. If the fluid removed is thick, golden and stringy, complete diagnosis can be made. X-rays, ultrasounds or computed tomography can confirm that no other underlying issue is present. Full blood work should be run, including a complete blood count and serum chemistry to show the overall health of the cat.

Very mild cases of gland swelling may not require treatment. Advanced cases of mucoceles can interfere with the breathing process and prevent the cat from eating. Fistulas may become infected, which can then spread throughout the body.

In both types of salivary gland swelling, removal of the damaged gland can completely eradicate the issue. Sometimes an entire chain of glands need to be removed, while other in other instances, only one gland needs to be excised. Incision size will depend on the affected gland. General anesthesia is required for this procedure. When a mucocele is present, it is lanced and drained before the gland is removed. It may help to also perform a marsupialization procedure while removing the gland. 

In the case of a fistula, surgically tying off the damaged duct can help to stop saliva leakage.

If infection is present, or if surgery has been performed, antibiotics will be prescribed to eliminate harmful bacteria. Prescriptions generally last from one to four weeks.

After oral surgery, close monitoring will be needed to ensure the incision site heals without becoming infected. Soft foods may be necessary until the cat can properly chew. Administer all painkillers and antibiotics that have been prescribed by your veterinarian. Eliminating stress in the home and limiting your cat’s activity can promote quick healing. 

Your cat will be scheduled for a post-surgery checkup appointment to ensure the incision is healing and that the surgery was performed correctly. If the surgical removal of the gland is successful, often no more related issues will occur in the cat. As the causes of salivary mucoceles and fistulas is vastly unknown, it is hard to prevent them from developing in the first place.